Typewriter display device



May 5, 1942.

T. J. WATSON, JR

TYPEWRITER DI SPLAY DEVICE Filed Dec. 31, 1940 ATTORNEY.

Patented May 5, 1942 TYPEWRITER DISPLAY DEVICE Thomas J. Watson, Jr., New York, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application December 31, 1940, Serial No. 372,474

4 Claims.

This invention relates to display devices for illustrating the ease of operation of the individual keys of a typewriter or other key-controlled machine.

In advertising displays pertaining to typewriters or, as a matter of fact, to most any machine provided with a keyboard, one of the selling points usually stressed is the feature commonly known as the lightness of touch of the keys, and it is quite important that this be demonstrated in some novel and convincing manner.

Accordingly, it becomes the general object of the instant invention to provide an improved display means for demonstrating the amount of force required to depress the individual keys of a typewriter keyboard or the like.

More specifically, it is proposed to provide a robot device which operates the typewriter in such a manner as to approximate natural operating conditions and which lends itself particularly to display purposes.

For the specific structure of the robot device, it is contemplated to employ a constantly rotating cam mechanismfor raising and lowering weights of known values on the typewriter keys.

In order that the true force necessary for the depression of the keys may be properly illustrated, the weights are lowered gently on the keys. On the other hand, in order to speed up operations and at the same time prevent the attempted operation of more than one key at a time by the weights, provision is made for raising the weights rapidly after they have effected depression of their associated keys.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

The drawing shows a sectional view of the typewriter and robot in operating relationship.

The invention is shown in the drawing as applied to a power driven typewriter of a well known type, the principles of which are disclosed in Patents 1,777,055 and 1,873,512, although its use is not limited to such machines. In the illustrated machine, briefly, depression of a character key 6 releases a latch 1 from a cam 8 permitting a spring-pressed lever 9 to move the cam against a continuously rotating motor-driven power roller H). The cam is rotated by frictional contact with the power roller in a clockwise direction, as viewed in the drawing, to cause the rocking of the cam carrier member II to depress a link l2. Depression of link I2 rocks a linkage I3 to propel the type bar I4 towards the platen 15, causing the type on the type bar to print on the sheet positioned on the platen.

The carriage return key 5 operates carriage return means such as disclosed in Patent No. 1,955,614. Depression of key 5 releases latch 1a from cam 8a to permit spring-pressed lever 91!. to move the cam into engagement with power roller 10. It will be noted that cam 8a difiers in shape from cam 8 in that it is a single rather than double lobe cam. The reason for this is simply to permit cam 8a to turn one complete revolution upon engagement with the power roller rather than one half revolution as does cam 8. Rotation of cam 8a in a counterclockwise direction by power roller l0 causes rocking of cam carrier member Na and depression of link No to eifect a carriage return operation. In this type of machine, carriage return operations are accompanied by an automatic line spacing of the sheet positioned on the platen 85.

For robot control, the typewriter is placed on a supporting base 20 and is positioned so that the front of the casing 21 is flush with a stop 22 fixed to the base. rubber mountings, usually four in number, which support the typewriter over the base 20.

A large standard 25 is fixed to base 20 and extends upwardly to support one end of a powerdriven shaft 26 journaled therein, the other end of which is supported in a parallel standard (not shown) extending upwardly from the base. Shaft 26 may be rotated at a fixed speed by any suitable power means. Fastened to the shaft for rotation therewith are a plurality of circular disks 21 having radial slots 28 cut at spaced points around their periphery to receive insertible. cam elements 29. For carriage return control, a single cam element 29a is placed in a slot in the disk 21 which has been provided for this purpose. The arrangement is such that by the time the disk has completed a revolution, thecharacters required to make up a line of information will have been printed. A carriage return is then efiected by the operation of key 6 under control of cam element 29a in the same manner as cam elements 29 control the character keys to effect character printing, which operations will now be explained.

A lever 30 is associated with each disk, the lever being pivotally mounted above the disk on a shaft 3| supported by standard 25. The lever is biased in a clockwise direction by a spring 32 connected to a bracket 33 on the standard 25, the right edge of the bracket forming a stop for the lever in its normal position. During the course of rotation of the disks 21, the cam elements 29 of those disks engage the lower arms of levers 30 and move them in a counterclockwise direction. A wire 34 is connected to the upper arm of each lever 30 and runs over a pulley 35 to a weight W of known value, which value is just enough to operate a key. Thus, counterclockwise movement 23 represents one of the,

After one of the cam elements 29 has engaged I a lever 30, this element soon passes beyond the lower tip of the lever due to the continued rotation of disk 21. As soonas this occurs, spring 32 becomes active to return lever 30 quickly to its normal position and thus raise the connected weight W rapidly from its position on key 5.

Carriage return is effected by cam element 29a engaging lever 3011 which is connected by a wire 34a running over pulley 35a to another weight W. This weight is lowered gently on carriage return key 6 and raised rapidly from this key Just as was explained above for character key operation.

In order that no two keys of this typewriter will be attempted to be operated simultaneously by the robot, it is necessary to keep the cam elements 29 in relatively different positions on their associated disks. In other words, only one of the cam elements 29 of the entire robot should be operatively engaging its related lever 30 at a time. In this way the typewriter can be made to print a line of information similar to normal operation and to then eifect a carriage return and line space. It is understood that the robot mechanism may be connected for considerably more typewriter control functions than those actually disclosed. For the sake of simplicity, however, the description and drawing herein have been confined to the operations of the character keys and of the carriage return.

While there has been shown and described and pointed. out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A display device for demonstrating the ease of operation of a typewriter key or the like comprising, in combination, a weight of known value just capable of operating said key if placed at rest on said key, a rocker lever connected to said weight by a wire, means for movably mounting the weight over the key so that rocking movement of the lever causes vertical movement of the weight, a spring connected to the lever for biasing said lever to a normal position and the weight to a raised position, a revolving disk, a cam element carried by said disk for engaging the rocker lever in the course of rotation of the disk to impart a controlled movement to the lever, thereby causing the weight to drop slowly into position to rest on the key and to operate the latter, the cam element then releasing the lever for relatively rapid restoration by the spring to effect a quick return of the weight to its raised position.

2. A display device for demonstrating the ease of operation of a typewriter keyboard or the like comprising, in combination, a plurality of weights one for each or the keys of said keyboard, each weight being of a valuejust capable of operating a key it placed at rest on said key, a plurality of rocker levers one for each of. the weights and connected to said weights by individual wires, means supporting the weights over the keys for vertical movement upon rocking movement of said levers, spring means connected to said levers for maintaining the weights normally in a raised position, a plurality of revolv 'ing disks one for each rocker lever, and cam elements carried by said disks and positioned thereon for engaging said levers at predetermined times and in a predetermined sequence to cause the connected weights to be lowered slowly into position to rest on the keys and cause operation of said keys, said elements being arranged to release said levers upon continued rotation of the related disks so as to cause the weights to be restored quickly to the raised position by the spring means.

3. The combination with the keyboard of a typewriter or similar machine, of a robot attachment comprising a number of weights equal to the number of keys on said keyboard, the value of each of said weights being just sufiicient to depress a key if allowed to rest on said key, a rocker lever connected to each of said weights by a wire, common supporting means for said levers and said wires for causing the weights to be suspended directly over the keys, springs respectively connected to the levers for maintaining said levers in normal position and the weights in a lifted position, a rotatable disk aligned with each of the rocker levers, and striker elements positioned on the disks for operation of the rocker levers in predetermined sequence during the course of rotation of said disks. each striker element, upon engaging its related rocker lever, causing a controlled movement of said lever to lower the connected weight into position to rest on one of the keys and cause operation thereof, and immediately thereafter releasing the engaged lever for restoration to the normal position by the connected spring, thereby causing the weight to be returned to its lifted position.

4. The combination with the keyboard of a typewriter or similar machine, of a robot attachment comprising a plurality of rotating disks one for each of the keys of the keyboard, a pivoted lever adjacent each of said disks, a plurality of weights of known value just capable individually of causing operation of a key if placed at rest on said key, a flexible connection between each weight and each lever, means for supporting said weights over the keys, spring means connected to the levers for maintaining the weights normally in a lifted position, and striker means carried by each disk during the course of rotation of said disk for effecting a rocking movement of the adjacent lever at a predetermined time in a direction tending to create slack in the flexible connection, to be taken up by the force of gravity on the associated weight, to cause said weight to be lowered into position to rest on one of the keys and operate said key, the striker means then releasing the lever for restoring movement by the spring means which also returns the weight to its lifted position.

THOMAS J. WATSON, JR. 

